The general thing to take note of here is that whatever appears after the tag name will be stringified and sent to the second argument of initialize, so for example, a custom tag that looks like:

{% my_tag lol this is a tag %}

args in the initialize method above will be lol this is a tag (note the trailing whitespace). There’s no further treatment, so you will have to parse the string yourself somehow to identify what is what, and then assign what you need to instance variables: